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Obesity
This page contains the findings of systematic reviews undertaken by the EPPI-Centre Health Promotion and Public Health Reviews Facility

Children's views
Young people's views
Sedentary behaviour
Educational attainment
Social and environmental interventions
The use of incentives
Schemes to promote healthy weight
References

See also (the links below close this page and take you to a different one)
Healthy eating
Physical activity

The government has identified obesity as a priority, and there is considerable policy interest in the UK and internationally in tackling the problem of overweight and obesity in children and young people.

Children’s views [3]

Children are likely to experience immediate physical and psychosocial problems as a result of being obese and are at a higher risk of obesity as they grow older. Children’s attitudes to and beliefs about their bodies, which can include high levels of body dissatisfaction, have also raised concern. This systematic review examines recent research findings from the UK where children aged from 4 to 11 provide views about their own body sizes or about the body sizes of others.

Children experience obesity largely as a social problem. However, whatever their body size, they often may not consider the health consequences of obesity to be important. They are highly aware of body size and our society’s attitudes towards it, appear to be aware of the actual size of their own bodies and are likely to have judged the acceptability of their own body. Many are dissatisfied and some feel anxious despite having a healthy body size. Girls are likely to want to be leaner, regardless of their size. Many boys and girls aspire to very lean body shapes that are unattainable and likely to be unhealthy. Very overweight children, experience body size as a big problem. They are likely to experience unhelpful responses to their own body sizes from other children, as well as adults. Fat-related name calling and bullying is considered to be a normal occurrence. They encounter many barriers, and a lack of support, when they try to take action to reduce their size. Parents and friends appear to be the most helpful source of support, but this is not always unproblematic.

While very overweight children and girls bear the brunt, the combined impact of our obesogenic environment and our society’s ongoing preoccupation with body size appears now to be affecting the body image ideals and body satisfaction of boys as well. Girls and boys aged under 12, however, differ considerably, both in their aspirations for their bodies and ideas about others’ bodies.

Young people's views [7]

The review found that young people discussed larger body sizes in overwhelmingly social terms. An overweight body size was to be avoided for social, rather than health reasons. Among young people with healthy weights, these reasons included not being attractive to others and having fewer friends. Young women and men identified ideals consistently for their own bodies that were very different for the two sexes. Young women were identified as being particularly concerned about body size, but young men’s concerns were also discussed. The accounts of young people with experience of being obese also made reference to the social nature of size, but the consequences appear far graver. These young people reported how their size had impacted seriously on their ability to socialise with their peers, and had also led to severe and unrelenting size-related abuse and a sense of isolation and of being marked out as being unacceptably different.

Young people also emphasised personal responsibility when talking about body size. Regardless of their own size, they also tended to be judgemental of, and to apportion blame to individuals who were very overweight, identifying this as due to a lack of willpower. And yet overweight young people, when reporting their experiences of trying to lose weight, described a social environment that contained multiple barriers in the way of their success. They described experiences of surveillance and abuse while exercising or attempting to eat healthily, unhelpful food environments at home, and the receipt of unhelpful advice and criticism from others. These young people reported how, as a result, they withdrew from social contact, avoided school-based physical activity and ate for comfort. Their accounts also described the vicious circle of increased weight gain, guilt and otherwise lowered mood that such strategies can incubate. In contrast, the few, positive accounts of weight-loss attempts emphasised the benefits of contact with others who were going through, or had gone through, similar experiences.

The accounts of young people who had experience of being very overweight included numerous references to emotion and well-being. As well as the feelings of exclusion, shame and lowered mood described above, they reported frustration at the time required for substantial weight loss, and fear that weight might easily rebound. Good mental health was seen as key for substantial weight-loss and having taken active steps to reduce weight was a source of considerable pride, especially when successful.

Young people in the UK had not been asked by researchers to reflect to any great extent on what might help them achieve and maintain a healthy weight. This review suggests, again, that young people will tend to focus on their own behaviour. As well as making more careful efforts to eat healthily and take exercise, young people in this review mentioned the need for them to access their own psychological resources. Only one study in this review included reference to what other people should do. Here, young people, many of whom had experience of trying, and sometimes succeeding, in losing substantial amounts of weight, emphasised how health professionals and others should be less judgemental, and give encouragement and other, practical, forms of support.  

Sedentary behaviour [5]

A systematic map aimed to review the scope of the quantitative research literature on the relationship between obesity and sedentary behaviour in young people aged 6-16 and 326 relevant studies were identified. The majority of studies were conducted in the United States, followed by Canada and Australia. Only 15 were undertaken in the UK. Studies covered both primary and secondary school age ranges and most covered both boys and girls.

Studies used a variety of different measures of sedentary behaviour. The most frequent measure was time spent in TV, film and video viewing or a proxy for this, such as TV in the bedroom or number of TVs in the house. This was followed by computer use/playing computer games/owning a computer and playing video games. Most studies use Body Mass Index (BMI) as an indicator of obesity. Most studies explored the relationship between obesity and sedentary behaviour. There were 197 studies which attempted to assess the effect of sedentary behaviour on obesity, 65 studies aimed to assess the effect of obesity on sedentary behaviour, and 8 studies assessed both. In addition there were 41 intervention studies that attempted to manipulate sedentary behaviour and assess its effect on obesity.

Educational attainment [6]

Some research suggests that there may be a relationship between obesity and poor educational attainment. It is likely that obesity and poor school performance are elements of a broader picture of inequalities in health and education, whereby disadvantaged socio-economic groups tend to have poorer health and lower levels of education. It is also possible that other factors influence obesity and attainment, such as gender, discrimination, and poor mental and emotional well-being.

Twenty-nine studies on the link between obesity and educational attainment were reviewed. While often conflicting, an overall pattern emerges from the research evidence suggesting that there is a weak negative association between obesity and educational attainment in children and young people; i.e. that higher weight is associated with lower educational attainment. However, obesity appears to be associated with other variables, such as socio-economic status, and when these other variables are taken into consideration, the association between obesity and attainment becomes still weaker, and often loses statistical significance. Specifically, place of residence, ethnicity, occupation, gender, religion, education, socio-economic status and social capital were all explored as potential moderating variables in the included research. The most commonly explored moderating variable was socio-economic status, which was tested in 23 of the 29 studies.

Most studies explored the influence of obesity upon attainment. Only two studies examined the influence of attainment upon obesity. Many authors suggested multiple causal pathways, many of which remained untested in their studies. The moderating variables used in statistical analyses of the relationship between obesity and attainment were not consistent with the causal pathways proposed, which is probably a reflection of the constraints imposed upon authors conducting secondary analyses of pre-existing datasets (i.e. they made use of existing variables, rather than collecting their own, tailored data). The most frequently cited factors resulting from obesity and impacting upon educational attainment were poor mental health, stigmatisation and discrimination, disordered sleep, decreased time spent in physical activity and socialising, and absenteeism.

In sum, various factors appear to be associated with obesity which contribute to low educational attainment to some extent. Given the variation in definitions, analyses and quality of data, it is impossible to point to any causative or definite risk factors.

Social and environmental interventions [2]

There is increasing interest from both policy-makers and researchers in the social and environmental factors which influence obesity. These factors include the physical environment, social values, technology and the economy. Interventions that aim to change social and environmental factors in order to reduce obesity may include taxes or subsidies to encourage healthy eating or physical activity, extra provision of sporting facilities, efforts to improve safety and accessibility of walking and cycling or play areas or attempting to influence the social meanings and values attached to weight, food or physical activity.

This systematic map identified 54 reviews, of which 32 were systematic. Most of the reviews covered the population as a whole and did not have a specific focus on children or young people. The reviews covered a wide range of intervention types and settings. Some were focused on specific intervention strategies such as mass media campaigns, financial instruments or point-of-sale information. Some investigated multi-component interventions which integrated social and environmental change with education and strategies for individual behaviour change, in either school or community settings. A number of reviews included studies covering all of these areas.

Many reviews focused on studies which evaluated interventions aiming to alter the social values attached to food and exercise, using, for example, education or social marketing techniques. Few reviews were found which included studies evaluating large-scale structural changes to the physical environment or the availability or cost of food, exercise or sport.

The use of incentives [4]

A systematic map of studies which evaluated the use of incentives to tackle obesity, physical activity, diet and weight management behaviours found 61 studies, of which 56% included adults, 20% young people, 32% children, and 17% the general population. A third of the studies focused on females, and no studies targeted males only. Fifteen studies (25%) explicitly evaluated the use of incentives in low income populations, of which three were systematic reviews: two were of nutritional interventions with women with an emphasis on improving levels of healthy eating in pregnant and non-pregnant women, and one was of nutrition and physical activity interventions with low income populations. The remaining 12 studies varied in their focus and outcomes, and there was no coherent group of studies which appeared to focus on obesity or weight management. Six studies evaluated interventions in minority ethnic populations, all of which were conducted in the USA. Overweight or obese populations were targeted in 13 (22%) of the interventions evaluated. Only 38 (63%) of the studies reported whether incentives were given contingent on behaviour change or achieving a particular goal; sixteen were contingent and 22 non-contingent. There was a broad range of incentives provided, with financial incentives being the most common. Other incentives included access to free or reduced cost resources (29%), mainly food-related, with no studies providing increased access to healthier foodstuff (e.g. in snack vending machines in school), or reduced cost healthy produce (e.g. in staff canteens); one study provided new mothers with a sports stroller, and one compared lower cost health insurance with a cash incentive. Vouchers were all exchangeable for health food items in different settings (e.g. local farmers market, supermarket), apart from one study which provided vouchers for accessing sport and leisure facilities, and two which were unclear.

A database of schemes to promote healthy weight [1]

The Department of Health (England) commissioned the EPPI-Centre to produce a report [5] and associated searchable database to summarise schemes for promoting health weight in England. In order to be included in the database, schemes needed a primary focus on tackling overweight or obesity in school-age children (4-18 years) who were already overweight or obese, through dietary, exercise or other means. Included interventions had to be structured and sustained over a period of time. The data cover the content and running of the scheme, as well as what monitoring or evaluation had taken place.

References

1. Schemes to promote healthy weight among obese and overweight children in England (2008)

2. Social and environmental interventions to reduce childhood obesity: a systematic map of reviews (2008)

3. Children’s views about obesity, body size, shape and weight: a systematic review (2009)

4. Incentives to improve smoking, physical activity, dietary and weight management behaviours: a scoping review of the research evidence (2009)

5. A systematic map of the research on the relationship between obesity and sedentary behaviour in young people  (2009)

6. Childhood obesity and educational attainment: a systematic review (2011)

7. The views of young people in the UK about obesity, body size, shape and weight: a systematic review (2013)

  
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